Revert some use of PtrKey to fix parallel_queries build

src/librustc/ty/query/job.rs

@@ -11,7 +11,6 @@
 #![allow(warnings)]
 
 use std::mem;
-use rustc_data_structures::ptr_key::PtrKey;
 use rustc_data_structures::sync::{Lock, LockGuard, Lrc, Weak};
 use rustc_data_structures::OnDrop;
 use syntax_pos::Span;
@@ -283,7 +282,7 @@ where
 fn cycle_check<'tcx>(query: Lrc<QueryJob<'tcx>>,
                      span: Span,
                      stack: &mut Vec<(Span, Lrc<QueryJob<'tcx>>)>,
-                     visited: &mut HashSet<PtrKey<'tcx, QueryJob<'tcx>>>
+                     visited: &mut HashSet<*const QueryJob<'tcx>>
 ) -> Option<Option<Waiter<'tcx>>> {
     if visited.contains(&query.as_ptr()) {
         return if let Some(p) = stack.iter().position(|q| q.1.as_ptr() == query.as_ptr()) {
@@ -322,7 +321,7 @@ fn cycle_check<'tcx>(query: Lrc<QueryJob<'tcx>>,
 #[cfg(parallel_queries)]
 fn connected_to_root<'tcx>(
     query: Lrc<QueryJob<'tcx>>,
-    visited: &mut HashSet<PtrKey<'tcx, QueryJob<'tcx>>>
+    visited: &mut HashSet<*const QueryJob<'tcx>>
 ) -> bool {
     // We already visited this or we're deliberately ignoring it
     if visited.contains(&query.as_ptr()) {